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Biomedical subjects

A K Ray

Publications and source records attributed to A K Ray.

At least 37 records · Page 2Linked to original sources
PubMed1987

Induction of hepatic mitochondrial alpha-glycerophosphate dehydrogenase by L-triiodothyronine in Singi fish (Heteropneustes fossilis Bloch).

A single injection of L-triiodothyronine (T3) in different doses (0.25, 0.5, 5, 20 and 50 micrograms/g) increased the hepatic mitochondrial cytochrome-linked alpha-glycerophosphate dehydrogenase (alpha-GPD) activity and mitochondrial protein content of Singi fish, as observed on the 3rd day. A non-linear dose-response relationship with respect to enzyme activity was observed with different doses of T3. A low dose of 0.1 micrograms of T3 per g failed to cause any change in alpha-GPD activity and mitochondrial protein content of the liver. The enhancement of alpha-GPD activity over the control level with a low and a high dose of T3, viz., 0.5 and 5 micrograms/g, was followed from the 1st to the 7th day, when it was found that enzyme activity reached the maximum level on the 3rd day and then gradually declined to the control value on the 7th day. The percentage increase in enzyme activity with 5 micrograms/g was higher than that with 0.5 microgram/g from the 2nd to 5th day. Compared to the control, these two doses of T3 caused an increase in alpha-GPD activity from the 1st to the 6th day. Cycloheximide inhibited the T3-induced increase in alpha-GPD activity, mitochondrial and total protein content of liver. Immersion of Singi fishes in thiourea-containing (1 mg/ml) medium for 30 days showed a fall in hepatic alpha-GPD activity in comparison to the euthyroid control. A single injection of T3 (0.5 microgram/g) to the hypothyroid fish recovered alpha-GPD activity to more than the euthyroid control level. An increase in mitochondrial protein content in the T3-injected hypothyroid fish has been observed. DNA content of the fish liver remained unchanged in every experimental condition. The results thus showed the significant responsiveness of the fish liver to thyroid hormone.

Animals↗
PubMed1986

Thyroid hormone-induced changes in different ion-specific adenosine triphosphatase activities in liver of Singi fish Heteropneustes fossilis (Bloch).

A single injection of different doses of T3 (0.5, 5, 20, and 50 micrograms/g) to Singi fish caused an increase in Na+K+-ATPase activity in crude liver homogenate in a dose-dependent non-linear fashion on the 3rd d. Ca++- and Mg++-ATPase activity increased only with 20 and 50 micrograms/g of T3. Lowering the dose of T3 to 0.1 microgram and 0.25 microgram/g in a single injection had not effect on these enzyme activities. TETRAC (1, 2, and 4 micrograms/g) and TRIAC (2 and 4 micrograms/g) in a single injection enhanced the activities of Na+K+-ATPase, but Ca++- and Mg++-ATPase activities remained unchanged on the 3rd d. Immersion of Singi fish in thiourea-containing medium (1 mg/ml) for 30 d caused reduction in Na+K+-ATPase activity, but Ca++- and Mg++-ATPase activity remained unaltered. The reduced level of Na+K+-ATPase activity in the thiourea-treated hypothyroid fish was recovered and even brought above the control level by a single injection of T3 at the dose of 0.5 microgram/g. Differential sensitivity of various ion-specific ATPases to T3 in liver of Singi fish is thus documented.

Animals↗
PubMed1986

Functional scanning electron microscopical observations on the oral roof in an air-breathing teleost, Clarias batrachus (LINN.).

Scanning Electron Microscopical (SEM) as well as light microscopical features of the oral roof including barbels of the air-breathing teleost, Clarias batrachus (LINN.) have been described in relation to its feeding habit. 3 distinct types of taste buds have been recorded for the first time in the barbels, lip, and in and around the teeth bearing suprapharyngeal teeth pad of the fish studied. The taste buds in the barbels and lip are elevated over the epithelium and confer wart like appearance which probably help in mechanoreception in addition to chemoreception. The taste buds in the suprapharyngeal teeth pad slightly rise above the epithelium whereas those in the borders of it do not. They also possess numerous minute papillae in the gustatory pores. These taste buds seem to act as chemoreceptors. SEM and light microscopical observations on the structure and distribution of taste buds in the oral roof clearly reveal that the fish is purely a taste-feeder and scans and gropes the food materials from the bottom of the pond.

Animals↗
PubMed1978

Immunoglobulin (Gm) allotypes in a sample of Canadian Ashkenazic Jews.

Gm typing on the serum specimens of 507 Ashkenazic Jews (pre-dominantly of Polish-Russian ancestry) from Toronto, Canada has established the presence of haplotypes Gm3;5, Gm1;21, Gm1,2;21, and Gm1,17;5, and the absence of haplotypes Gm1;13,15,16, Gm1;5,6, and Gm1;5,6,24 which have been found in other Jewish peoples. It is suggested that Ashkenazic populations have lower frequencies of haplotype Gm1,17;5 than non-European Jewish populations, and that some eastern European Jewish populations have acquired the Gm1;13,15,16 haplotype through gene flow from Central Asia. Thus Jewish populations show differences in the Gm system; many of the differences may be in the direction of similarities to neighbouring non-Jewish populations.

Canada↗
PubMed1977

Effects of prostaglandins E2 and F2alpha on lecithin biosynthesis by cultured lung cells.

Transformed cells from human lung carcinoma (Line A549), resembling type II pneumocytes, were cultured in monolayer at 37 degrees C and incubated for five hours with 3H-choline and 14C-palmitate in the presence of various concentrations of prostaglandins (PGS) E2 and F2alpha. In the control (no PG) the level of % palmitate incorporation was 13.5 x as high as that of choline, after taking isotope dilution into account. Between the concentrations studied, 0.1 and 10 muM, both prostaglandins stimulated markedly the incorporation of both precursors, though choline up to 3 x better than palmitate. This was indicated by a change in the palmitate/choline incorporation ratio from 13.5 to as low as 4.2. At the lowest PG concentration, 0.1 muM, PGE2 was much more effective than PGF2alpha in stimulating the incorporation of both precursors.

Cell Line↗
PubMed1977

Morpho-histology of the alimentary canal of an Indian fresh-water perch, Colisa fasciata (Bloch) in relation to food and feeding habits.

The morpho-histology of the alimentary canal in an Indian freshwater perch, Colisa fasciata (Bloch) in relation to food and feeding habits has been described. C. fasciata is an omnivorous, mid-feeder. The mouth is protractile. The alimentary canal comprises the lip, buccal cavity, pharynx, oesophagus, stomach, pyloric caeca, a long and coiled intestine and the rectum. The teeth on the roof and floor of the buccal cavity, jaw teeth, pharyngeal teeth and horny pad teeth are all adapted to the nature of the food ingested. The nature and disposition of taste-buds and mucous cells on the lips suggests that the fish is a taste-feeder. The presence of taste-buds in the anterior oesophagus indicates that the gustatory sense extends upto the oesophagus. The stomach is divided into the cardiac and pyloric regions. The surface epithelium of the cardiac stomach secretes mucous and the glandular epithelium contains numerous gastric glands. The pyloric caeca are paired. The intestine is divided into anterior, middle and posterior regions. The R.L.G. (relative length of the gut) varies from 4--5. Mucosal folds are simple.

Animals↗
PubMed1976

Isolation of secretory IgA from a lung surfactant fraction.

Although dipalmitoyl lecithin, is the essential component of the pulmonary surfactant system that is invoked for alveolar stability, there is no explanation as yet for the origin and role of certain proteins that are found with the phospholipid in pulmonary washings. Aqueous lavages obtained from rabbit lung contain three major proteins, two of which are serum proteins (albumin 60%, gamma-globulin 10%), and the third, protein "T" (20%), is described here as pulmonary secretory immunoglobulin A (sIgA1. The protein is first recovered quantitatively in the surface active lipid-protein fraction from filtration of pulmonary lavage on Sephadex G-200. The protein is then isolated from the lipid either by filtration on SDS-Sephadex G-200 or by ethanol-ether precipitation. After reductive cleavage with either mercaptoethanol or dithiothreitol and alkylation with iodoacetamide, three protein peaks are obtained from SDS-sephadex G-200 separation. The products of reductive cleavage are analogous to the secretory component (MW approximately 60,000), H-chain (MW approximately 50,000), L-chain (MW approximately 25,000), and J-piece (MW approximately 28,000) of secretory IgA from colostrum. In immunodiffusion the lung protein and colostrum sIgA show striking identity lines, as do antibodies to rabbit colostrum and to the lung protein. Amino acid and carbohydrate analyses reveal some differences between the two secretory immunoglobulins. Although this protein has been found together with the phospholipid surfactant of the lung in vitro, the present structural study concludes that the protein is sIgA. Although concurrent immunofluorescence studies showed that this protein is in the alveolar lining layer, we cannot as yet conclude that it belongs to the surfactant system of the lung.

Amino Acids↗